Today we'll do a simple run through of a valuation method used to estimate the attractiveness of SDI Limited (ASX:SDI) as an investment opportunity by taking the expected future cash flows and discounting them to their present value. This will be done using the Discounted Cash Flow (DCF) model. Models like these may appear beyond the comprehension of a lay person, but they're fairly easy to follow.

Remember though, that there are many ways to estimate a company's value, and a DCF is just one method. If you still have some burning questions about this type of valuation, take a look at the Simply Wall St analysis model.

Check out our latest analysis for SDI

Is SDI fairly valued?

We have to calculate the value of SDI slightly differently to other stocks because it is a medical equipment company. Instead of using free cash flows, which are hard to estimate and often not reported by analysts in this industry, dividends per share (DPS) payments are used. Unless a company pays out the majority of its FCF as a dividend, this method will typically underestimate the value of the stock. The 'Gordon Growth Model' is used, which simply assumes that dividend payments will continue to increase at a sustainable growth rate forever. For a number of reasons a very conservative growth rate is used that cannot exceed that of a company's Gross Domestic Product (GDP). In this case we used the 5-year average of the 10-year government bond yield (1.8%). The expected dividend per share is then discounted to today's value at a cost of equity of 5.7%. Compared to the current share price of AU$0.8, the company appears around fair value at the time of writing. Valuations are imprecise instruments though, rather like a telescope - move a few degrees and end up in a different galaxy. Do keep this in mind.

Value Per Share = Expected Dividend Per Share / (Discount Rate - Perpetual Growth Rate)

= AU$0.03 / (5.7% – 1.8%)

= AU$0.8

The assumptions

We would point out that the most important inputs to a discounted cash flow are the discount rate and of course the actual cash flows. If you don't agree with these result, have a go at the calculation yourself and play with the assumptions. The DCF also does not consider the possible cyclicality of an industry, or a company's future capital requirements, so it does not give a full picture of a company's potential performance. Given that we are looking at SDI as potential shareholders, the cost of equity is used as the discount rate, rather than the cost of capital (or weighted average cost of capital, WACC) which accounts for debt. In this calculation we've used 5.7%, which is based on a levered beta of 0.921. Beta is a measure of a stock's volatility, compared to the market as a whole. We get our beta from the industry average beta of globally comparable companies, with an imposed limit between 0.8 and 2.0, which is a reasonable range for a stable business.